In the Web tier of a Web-based three-tier application, usually, a plurality of computer resources equipped with the same application are prepared, and access requests for the service provided by the application are distributed to the plurality of computer resources by using a load distribution device and processed therein. In this distributed processing system, when the processing speed for the service is reduced due to the increase of the requests, a computer equipped with the same application is newly added and the settings of the load distribution device are changed so as to distribute the request also to the added computer. By doing so, the reduction of processing speed for the service can be avoided.
Japanese Patent Application Laid-Open No. 2002-24194 discloses the distribution of jobs with reference to the history of the jobs executed by the computer resources.